Tuesday, January 10, 2012

Another mild day today then Arctic blast moves in for Wednesday..

It'll be one more day of above freezing temperatures today over southern Manitoba before the well advertised blast of Arctic air moves in tonight into Wednesday. Temperatures today will once again flirt with record highs near +5c in Winnipeg, with milder readings to our southwest. This will be our 7th day so far this month with a daily high above the freezing mark, an amazing stat considering we typically see only 1 or 2 days above freezing all of January. But that will be the end of the mild weather for awhile as a sharp cold front pushes across southern MB tonight. This front will usher in a much colder airmass from the north along with occasional snow and gusty northwest winds overnight through Wednesday. Temperatures will fall to the minus 15C mark by Wednesday morning, and continue to drop during the day to minus 20C by evening. Windchill values (remember those?) will fall to the minus 30 range.. which will be a shock to the system after such a prolonged spell of mild weather (32 consecutive days above normal). The cold weather will persist through Thursday before a moderating trend this weekend. Get the cold weather gear ready.. more typical January weather is on the way!

I think 5 cm would be the most Winnipeg would see.. the front's moving through pretty fast, and the bulk of the snow will be moving to our north and east through the Whiteshell into NW Ontario. I figure about 2-4 cm for Winnipeg along with gusty winds giving drifting snow and local blowing snow mainly overnight through Wednesday. Heavier amounts possible towards the Ontario border.

Rob-What mean temps do we need each of next 4 days to add to our 32 consecutive day above normal streak.Also, what is the longest *Heart of Winter* streak of above freezing days*Mid December to Mid February

On another site Brad posted ..Normal daytime highs for this time of year are around -13°C and normal overnight lows are around -24°C. For the first time in over a month, Winnipeg will experience below-normal temperatures..

Officially temperature peaked at 5.1C late this morning at the airport, and temperatures dropped slightly this afternoon as clouds thickened up. So will likely end up just tying the record. I'll take it. Back to winter now...finally

The mean daily temperature (average between high and low) needs to be below -18.5C to break the above normal streak (that's our normal daily temperature right now, believe it or not). For Wednesday, the day's high will be whatever the temperature is at midnight tonight since temperatures will fall steadily through the day tomorrow. With the cold front not passing through Winnipeg until mid evening or so, we could still be at -2 or -3C by midnight which will be tomorrow's high. So we'd have to have a low of -35C or so tomorrow to go below normal for the day, which isn't likely. So tomorrow will likely still end up above normal, even though temps will be falling all day. It likely won't be until Thursday that we officially end the above normal streak.

As for above freezing streaks in Winnipeg, Jan 1942 saw 9 consecutive days with highs above freezing between the 16th and 24th, culminating with the all time January high of +7.8C on the 23rd. In fact, between the 11th and 24th that month, there was only one day out of 14 with a high below freezing. Amazing.

In our warmest winter ever of 1877-78, December saw only one daytime high below freezing between the 9th and 26th.. and that was only -1C on the 20th. Amazing warmth, especially for back then.

Looks like we'll see periods of snow developing in the deeper colder air behind the cold front, which looks like it will be through Winnipeg by 10 or 11 pm (currently through Dauphin where temps are dropping rapidly) We should see periods of snow developing overnight and continuing through Wednesday, tapering off Wednesday night. Snow won't be heavy, but we could see some heavier bursts from time to time, with reduced visibility. Winds will stay brisk through Wednesday and Wednesday night before gradually diminishing Thursday.

It's about 11:24pm and I can just hear the 1st gusts coming through now. Still can't see anything on the radar but the wind has really picked up in the last 10 mins. Was beautiful just before this with mostly clear skys maybe a bit of haze.

Snow has been slow to develop in Winnipeg, but it's still on the way for us. Area of snow through the Interlake with leading edge from Tuelon through Woodlands to Portage as of 7:30 am will be pushing into Winnipeg within the next couple of hours from the northwest.. Generally light snow expected, but radar indicating bands of heavier snow at times with visibilities of 1 mile or less, with the gusty winds giving occasional blowing and drifting snow. Looks like that should continue much of the day into this evening but accumulations shouldn't be much.. perhaps a couple of cm.. but it will be difficult to measure due to the winds. Bundle up!

I've picked up up about 3 cm of light fluffy snow as of 7 pm.. has been falling steadily past few hours now. Radar shows we'll still be in it for the next couple of hours before tapering off by midnight or so.. may pick up another 2-3 cm before it ends.

Up to a solid 5-6 cm of the driest, fluffiest snow you'll ever see.. water ratio is probably 30 or 40:1. Very dry.. you could sweep the stuff away instead of a shovel. Radar shows back edge of the snow just pushing across the northwest perimeter now.. so Winnipeg should be seeing the snow ending from the northwest to southeast over the next hour or so..

While we "dig out" from 6 cm of fluffy snow, consider these staggering snowfall stats from Valdez, AK which is getting pummeled by snowstorm after snowstorm on the southern coast of Alaska. Over the past 2 days, they've picked up 27" (70 cm) of snow. They've had over 91" (230 cm) of snow in the past 8 days, with 81" (205 cm) on the ground. Since Dec 1st, they've had a whopping 246" (625 cm) of snow. And there's more coming tonight and tomorrow. Click on my name for story and some impressive snowfall pics.

Yeah, we have a moderation this weekend as a clipper scoots by, then back into the deep freeze next week. Still some uncertainty regarding snowfall with that clipper Sunday into Monday.. model concensus taking bulk of snow through the interlake, although we should see some in the RRV. Regardless, we plunge back into the Arctic cold next week, but ensembles are hinting at moderating temps returning by the last third of January along with a possibly stormier pattern as a strong jet stream develops along the intl border. We'll see if that pans out..